In a video display device (liquid crystal display device) using a liquid crystal panel as a display device, various devisal for improving an average luminance and spatial luminance uniformity within a light emitting surface of a backlight for emitting light to the liquid crystal panel have been conventionally proposed in order to achieve high quality of a displayed image.
For example, Patent Document 1 has described that the luminance and luminance uniformity of the light to be emitted to the liquid crystal panel can be increased by arranging an optical element formed of two layers of a transparent layer on a light-source side and a diffusion layer on a liquid-crystal panel side between the light source (fluorescent tube, light emitting diode) and the liquid crystal panel, and providing a plurality of light shielding layers on a surface of or inside the transparent layer.